Supercharged steam generator for powerplant



g 2, 1966 W P. GORZEGNO ETAL 3,263,423

SUPERCHARGED STEAM GENERATOR FOR YONERFLAN'I 5 Sheets-Sheet 1 Filed June 10, 1965 LU. FZEUQZE'E'NU [.L/ll STEVENS 1.4. m. U J/H E J1 Aug. 2, 1966 Y W. P. GORZEGNO ETAL SUPERCHARGED STEAM GENERATOR FOR POWERPLANT Filed June 10, 1965 5 Sheets-Sheet 2 Aug. 2, 1966 w. P. sonzgewo ETAL 3,263,423

SUPERCHARGED STEAM GENERATOR FOR POWERPLANT Filed June 10, 1965 5 Sheets-Sheet 3 Aug. 2, 1966 w. P. GORZEGNO ETAL SUPERCHARGED STEAM GENERATOR FOR POWERILANT 5 Shea ts-Shee t 4 Filed June 10, 1965 00000 00000000 00000 00000 OOOOOOOQOOOOOO OOOOO OOOOOOOOOOOOQ Aug.'2, 1966 w. P. GORZEGNO ETAL 3,

SUPERCHARGED STEAM GENERATOR FOR POWERPLANT Filed June 10; 1965 5 Sheets- Sheet 5 United States Patent 3,263,423 SUIERCHARGED STEAM GENERATOR FUR PUWERPLANT Waiter lP. Gorzegno, Fiorham Park, and William D. Stevens, North Caldwell, Ni, and Luis A. Uriarte, San Francisco, Caiifi, assignors to Foster Wheeler Corporation, New York, N.Y., a corporation of New York Filed June 10, 1965, Ser. No. 462,862 6 Claims. (Cl. 6tl39.18)

This invention relates to the construction and operation of vapor generators and, more particularly, to the construction and operation of once-through vapor generators for use in a power plant which includes a gas turbine, a vapor turbine, and an air compressor driven by the gas turbine. Use of the terms vapor generator or steam generator includes not only generators which utilize water as the vaporizable fluid, but generators which utilize other vaporizable fluids as well.

Annual average generating costs of steam electric plants has been reduced historically by increasing the temperature and pressure at the turbine throttle thereby lowering the plant heat rate. Further improvement using this approach is usually not economically justified because of the excess costs of materials capable of service at the necessarily higher temperatures. In recent years, since system sizes have become much larger, there has been a trend towards progressively larger unit sizes as a means of reducing costs. However, a practical upper limit of single-unit, steam generator size is being reached at about the 1000 mw. level. One immediately applicable method of reducing steam generator first cost and possibly average annual generating costs, is to supercharge the steam generator by using a gas-turbine driven compressor to furnish combustion air. Hot exhaust gases issuing from the steam generator at high pressure drive the gas turbine. Since supercharging reduces the amount of heating surface required, resulting in size and weight reduction, great potential exists for reducing plant first cost by supercharging the steam generator of any steam cycle. This approach can be applied more advantageously to the once-through steam generator because the larger and costly steam drum is eliminated together with risers and downcomers which would require numerous penetrations of the outer or pressure containment shell. Furthermore, once-through circuitry permits greater freedom in surface arrangement and location. In addition, the circuit design, particularly in the furnace, can more easily accommodate the higher absorption rates.

The supercharged steam generating unit of this invention preferably utilizes a cycle in which the temperature of the gas through the gas turbine is raised to a high enough value so that the gas turbine furnishes power considerably in excess of that required to drive just a compressor to pressurize the steam generator. This excess power of the gas turbine is used to generate supplemental electricity in addition to that generated by power from the vapor-driven turbine. However, this invention can be utilized in a power plant in which only power from the vapor-driven turbine generates electricity.

Therefore, it is an object of this invention to provide a supercharged once-through vapor generator of improved and more economical construction and operation.

In accordance with this invention, a chamber formed of fin tubes is encased by an outer containment shell. The chamber has a first vertical section, a second vertical section, and a horizontal section. The first and second vertical sections are connected at their upper ends by the horizontal section. Air is supplied to burners located at the lower end of the first vertical section along a path which includes a space formed between the outer contain- 3,263,423 Patented August 2, 1966 ment shell and the chamber. Superheater tubes are located within the second vertical section and receive the heated fluid from the heating tubes forming the chamber at the lower end of the second vertical section. The superheater tubes are connected for series flow with the vapor turbine. Following partial expansion, as is the usual practice, the fluid is reheated in reheater tubes. The reheater tubes are located within the horizontal section and are connected for series flow from and to the vapor turbine. A control is provided to maintain a predetermined reheat temperature. The gases of combustion are discharged at the lower end of the second vertical section which is connected to the gas turbine.

The invention may be better understood from the following detailed description considered in conjunction with the accompanying drawings in which:

FIGURE 1 is a side cross-sectional view of the vapor generator.

FIGURE 2 is a top plan view along line 2-2 of FIG- URE 1 with the inner tube chamber removed.

FIGURE 3 is a schematic diagram showing the circuitry arrangement of the supercharged, once-through vapor generator in an electric power generating system.

FIGURE 4 is a side cross-sectional view of a control heat exchanger utilized for maintaining a predetermined reheat temperature.

FIGURE 5 is a cross-sectional view along line 55 of FIGURE 4.

FIGURE 6 is a schematic diagram of the control and bypass circuit on the tube side of the heat exchanger.

FIGURE 7 is a temperature-enthalpy diagram describing the operation of the invention.

FIGURE 8 is an enlarged cross-sectional view of a part of the fin-tube wall forming the inner tube chamber.

Referring now to the drawings and, more particularly, to FIGURE 1, an outer containment shell 21 encases the outside of the supercharged, once-through vapor generator. The outer containment shell 21 which is circular in cross section includes a first vertical portion 23 which is closed at the bottom end 25 and a second vertical portion 27 closed at its bottom end 29. The first vertical portion 23 and the second vertical portion 27 are connected by a top horizontal portion 31, which is also part of the outer containment shell 21. Located within the outer containment shell 21 is a chamber 33. The chamber 33 is formed from tubes 35 with fins 37 welded between the tubes 35 so that the chamber 33 is gas tight. The fin-tube chamber 33 includes a first vertical section 39 which is preferably cylindrical and has a diverging or bell-shaped extension 41 at its lower end. As best seen in FIGURE 1, the bell-shaped extension 41 expands outward toward the outer containment shell 21, and the largest cross-sectional area of the bell-shaped extension is just slightly smaller than or approximately equal to the inside cross-section of the first vertical portion 23 of the outer containment shell 21. This permits downward expansion of the first vertical section 39 as the tubes 35 and fins 37 expand from the heat of combustion. The first vertical section 39 of the chamber 33 is located within the first vertical portion 23 of the outer containment shell 21. A horizontal section 43 which is preferably rectangular in shape having a square cross-sectional area is located within the horizontal portion 31. The horizontal section 43 and the first vertical section 39 of the chamber 33 are interconnected by means of a tapered adapter 45, which reduces the cross-sectional area of the horizontal section 43. The tapered adapter 45 also connects the circular, first vertical section 3? with the square, horizontal section 43. Within the second vertical portion 27 of the outer or pressure containment shell 21, is the second vertical section 4-7 of the chamber 33. The second vertical section 47 is preferably rectangular in shape having a square cross-sectional area equivalent to the horizontal section 43 and is open at its lower end 46. A ring-shaped plate or baflie 49 extends between the outer containment shell 21 and the chamber 33 just above the open end 46. Between the outer containment shell 21 and the chamber 33 is air passageway 53. Below the sealing member 49 and within the second vertical portion 27 of the outer containment shell 21, a compartment 51 is formed. Air for the process of combustion enters the passageway 53 through air inlet ports 55 located in the second vertical portion above but adjacent to the baflle 49. The air admitted through the inlet ports 55 is thereby forced to flow upward through the air passageway 53. The baffle 49 prevents air from entering the compartment 51. Air exit ports 57 located through the first vertical section 23 just above the bell-shaped extension 41 serve to remove the air flow from the air passageway 53. Conduits 59 bent around in a U-shape, convey the air around the bellshaped extension 41 which obstructs continuation of the air passageway 53. The conduits 59 redeliver the air back into the outer containment shell 21 through air reentrance ports 61 located below the bell-shaped extension 41.

The bottom of the bell-shaped extension 41 is enclosed with a dish-shaped burner member 63. The burner member or panel 63 has ports 65 located through it into which burners 67 are placed. As best seen in FIGURE 2, the burners are evenly spaced about two concentric circles. As shown in FIGURE 1, the burners 67 are directed substantially at a common point along the longitudinal axis of the first vertical section 39. In this way, an even distribution of flame plasma is obtained and the flame is concentrated within the vicinity of the bell-shaped extension 41 which forms a flame basket. The bell-shaped extension 41 is packed with a plastic refractory (not shown) due to the extreme temperatures achieved in this vicinity. The burners 67 combust a mixture of the pressurized air and fuel, preferably natural gas or light oil. The hot gases of combustion travel upward and then back downward within the chamber 33 to the compartment 51 and then pass outside the containment shell 21 through gas exit ports 69.

Located within the horizontal section 43 of the chamber 33 are two reheater banks 71. The reheater banks 71 include a first reheater bank 73 preferably of platen design which is adjacent the'first vertical section 39 and a second reheater bank 75 preferably of pendant design which is adjacent the second vertical section 47. Connected between and located above the reheater banks 71 in the air passageway 53 is a control heat exchanger 77. A first reheater inlet header 79 is connected to the end of the first reheater bank 73 located closest to the first vertical section 39. A second reheater outlet 81 is connected to the end of the second reheater bank 75 located closest to the second vertical section 47. It should be noted that the two reheater banks 71 have parallel flow with the hot gases which makes possible a less costly alloy selection.

Located within the second vertical section 47 is a finishing superheater bank 83 having finishing superheater inlet headers 85 located at the bottom of the finishing superheater bank 83 and finishing superheater outlet headers 87 located at the upper end of the finishing superheater bank 83. Located within the second vertical section 47 below the finishing superheater bank 83 is a primary superheater bank 89. The primary superheater bank 89 has primary superheater inlet headers 91 located at the lower end of the primary superheater 89 and primary superheater outlet headers 93 located at the upper end of the primary superheater. Both primary and finishing superheater banks 89, 83 are in counter flow arrangement with the hot flue gases.

In considering the fluid circuit arrangement shown in FIGURE 3, comparison with FIGURE 7 is advisable. In FIGURE 7, a temperature-enthalpy diagram is shown for the vapor generator of FIGURE 1 arranged as shown in FIGURE 3 and utilizing water as the vaporizable fluid. The cycle conditions on which FIGURE 7 is based are 3500 p.s.i., 1000 F. superheat and 1000 F. single reheat. The gross terminal output from the vapor generator is 400 m.w. with an additional m.w. generated by the gas turbine. However, this is only by way of example, as this invention may be utilized with other cycle conditions and different capacities and in a power plant in which all the electric power is obtained through the vapor turbine.

Returning consideration to FIGURE 3, a vaporizable fluid, which is preheated by means of an economizer 95, enters the supercharged, once-through steam generator at a ring-shaped inlet header 97. The ring-shaped inlet header 97 is located directly beneath the dish-shaped burner panel 63. As best seen in FIGURE 1, within first mixer headers 99 the fluid is mixed to remove fluid enthalpy unbalance. Between the entrance header 97 and the first mixer headers 99 is the first pass of the steam generator. The second pass is from the first mixer headers 99 to second mixer headers 101 located at the top of the second vertical section 47. From the second mixer header 101, the fluid flow is through the inner boundary enclosure tubes 33 downward to a ring-shaped outlet header 103. The enthalpy pick-up from the enclosure tubes beyond the second mixer header 101 is shown in FIGURE 7 as encl. The flow then continues through a conduit 104 to the primary superheater inlet headers 91 and passes through the primary superheater bank 89 to the outlet headers 93 of the primary superheater bank 89 to the inlet headers of the finished superheater bank 83. Fluid exiting from the finishing superheater 83 then routes to a high pressure stage 108 of a vapor turbine 109. Referring to FIGURE 3, the turbine 109 besides having the high-pressure stage 108 has an intermediate-pressure stage 110 and a low-pressure stage 112. The turbine 109 drives an electric generator 114. Reheated steam is brought back from the turbine 109 preferably between the high-pressure stage 108 and the intermediate-pressure stage 110 through a conduit 116 to be reheated by means of the reheater banks 71. Fluid enters the reheater banks 71 through the inlet 79 and passes through the left reheater bank 73 into the control heat exchanger 77 in which high-pressure vaporizable fluid by-passed through a conduit 118 around the economizer 95 reduces the temperature of the reheat steam as is required. The bypassed vaporizable fluid is returned through a conduit 120 to flow into the ring-shaped inlet header 97. The reheat steam then passes through the right reheater bank 75 and exits through the reheater outlet 81 before returning to the turbine 109 through condit 122. A valve 124 located in the conduit 118 controls the flow of highpressure fluid through the control heat exchanger 77. The valve 124 receives a signal from the outlet of the reheaters 71 which determines the amount of flow of bypassed Water.

The hot gas leaving the four gas outlets 69 passes downward into connecting conduits 106 which merge the flow into two conduits 107 and then through a conduit 111 into an auxiliary fuel combustor 113, before entering a gas turbine 115. The auxiliary fuel combustor 113, as its name implies, burns additional fuel to increase substantially the energy input and to maintain a constant energy input to the gas turbine. The gas turbine drives a compressor 117 which supplies the compressed air into the air inlets 55 and into the auxiliary combustor 113 by means of an air conduit 119. The gas turbine 115 preferably having more power than is needed to drive the compressor 117 also drives an auxiliary electric generator 121 substantially smaller than the main electric generator 114. The exhaust gas from the gas turbine 115 passes through a conduit 123 through the economizer 95 to a stack 125, where it is discharged to the atmosphere.

As has been previously pointed out, the superheated vapor enters the high-pressure stage 108 of the turbine 109 and then is returned to the reheaters 71 where it is reheated before being delivered to the intermediate and lowqpressure turbines. The steam from the low-pressure turbine is condensed in a condenser 129 and is then pumped by a first feedwater pump 130 through the teedwater heaters 131 and by a second feedwater pump 132 through the economizer 95 and into the entrance header 97 as has been previously explained. The economizer 95 preheats the feedwater from the heat of the gases passing into a stack 125.

The control heat exchanger 77 removes excess heat from the reheat vapor and conveys it to high-pressure vaporizable fluid which lby-passes the economizer 95 but is fed with the vaporizable fluid from the economizer 95 into the inlet header 97 as has been previously described. As seen in FIGURES 4 and 5, the control heat exchanger 77 has a shell 13'1. Connected to the shell 131, preferably by welding, is a tube sheet 133. A tube sheet enclosure 135 encases the tube sheet 133 forming a compartment 137. Access to the compartment 137 is obtained by a removable plug 139. High-pressure vaporizable fluid enters the compartment 137 through an inlet 141. Extending from the tube sheet 133 are U-shaped tubes 143. The vaporizable fluid which is under high pressure cflows into the U-tubes and back out again into the compartment 137. A baflle 145 separates the inlet ends of the U-tubes 143 from the outlet ends. An outlet 147 serves to discharge the high-pressure water from the compartment 137 after it leaves the outlet ends of the U-tubes 143. The left reheater bank 73 has tubes 149 which flow into heat exchanger headers 151 one of which is shown in FIGURE 4. The heat exchanger headers 151 are connected to the shell 131 at approximately right angles to the longitudinal axis of the shell 131. The reheat steam enters the shell 131 from the headers 151 and flows over the outside of the U-tubes 143. Baflles 153 force the reheated steam to make a series of passes over the U-tubes 143. Tubes 155 of the right reheater bank 75 connect to the shell 131 to receive the steam as it finishes heating the U-tubes 143.

The control heat exchanger 77 eliminates the need for a parallel damper control system or gas recirculation system to maintain reheat control. Furthermore, the numerous technical difliculties of tilting burners is eliminated.

The entire structure is suspended from a frame 155. Suspension members157 extend from the frame 155 to support the entire once-through steam generator. The members 157 pass through the outer containment shell 21 to support the inner boundary enclosure 33. At each point where the members 157 penetrate the outer containment shell 21 they are securely welded to the outer containment shell 21. This suspension system makes possible the elimination of manholes which are a prime source of leaks. Should repairs be required, a hole can be cut with a torch. Since the unit is suspended, such an opening can be made without structural difliculties. Upon conclusion of the repairs, the hole can be welded closed.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of contsruction and the combination and arrangement of parts maybe resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. A vapor generator for use in a power plant which includes a gas turbine with an auxiliary combustor, a vapor turbine, and an air compressor driven by the gas turbine, comprising:

fluid heating tubes with fins therebetween defining a chamber, said chamber including a first vertical section, a second vertical section, and a horizontal section connecting the upper ends of said first vertical section and said second vertical section;

means for supplying a vaporizable fluid to said fluid heating tubes at the lower end of said first vertical section;

burner means located at the lower end of said first vertical section of said chamber for supplying heatinggases to said chamber for flow therethrough;

an outer containment shell for surrounding said enclosure;

means partially coextensive with said enclosure and outer containment shell for supplying air from said compressor to said burner means;

means for discharging said heating gases partially coextensive with said outer containment shell and connected to the lower end of said second vertical section and to said gas turbine through said auxiliary oornbustor;

means for structurally supporting said chamber and outer containment shell;

a superheater means located within the second vertical section of said chamber and connected for series flow of fluid from said fluid heating tubes at the lower end of said second vertical section and to said vapor turbine;

at reheater means located within the horizontal section of the chamber and connected for series flow of fluid from said vapor turbine and back to said vapor turbine; and

means for controlling the temperature of the fluid from said reheater means to said vapor turbine.

2. A vapor generator according to claim 1 wherein said means for controlling the temperature of the fluid from said reheater means includes a heat exchanger for cooling the fluid passing through said reheater means.

3. A vapor generator for use in a power plant which includes a gas turbine with an auxiliary combustor, a vapor turbine, and an air compressor driven by the gas turbine, comprising:

fluid heating tubes with fins therebetween defining a chamber, said chamber including a first vertical section, :a second vertical section, and a horizontal section connecting the upper ends of said first and second section;

means for supplying a vaporizable fluid to said fluid heating tubes at the lower end of the said first vertical section;

means for by-passing from and returning to said means for supplying a relatively cool vaporizable fluid a portion of said relatively cool vaporizable fluid before entering said fluid heating tubes;

burner mean-s located at the. lower end of said first vertical section of said chamber for supplying heating gases to said chamber for flow therethrough;

an outer containment shell surounding said enclosure;

means partially coextensive with said enclosure and outer containmnet shell for supplying air from said compressor to said burner means;

means for structurally supporting said chamber and outer containment shell;

a superheater means located within the second vertical section of said chamber and connected for series flow of fluid from said fluid heating tubes at the lower end of said second vertical section and to said vapor turbine;

a first reheater located in the horizontal section of the chamber and adjacent said first vertical section, said first reheater being connected for series flow of fluid from said vapor turbine;

a heat exchanger of the shell and tube type for controlling the temperature of the reheated fluid by removing excess heat from the reheat fluid and transferring said heat to the portion of said relatively cool vaporizable fluid by-passed from and returned to said means for supplying a vaporizable fluid, said means for by-passing and returning being connected to the tube side of said heat exchanger, the shell side of said heat exchanger being connected for series flow from said first reheater;

a second reheater located in the horizontal section of the chamber and adjacent said second vertical section, said second reheater being connected for series flow of fluid from the shell side of said heat exchanger; and

a temperature control valve located in series with the tube side of said heat exchanger and adapted to be actuated by the outlet temperature of said second reheater.

4. A vapor generator for use in a power plant which intube side of said heat exchanger and adapted to be actuated by the outlet temperature of said second reheater.

5. A vapor generator for use in a power plant which includes a gas turbine with an auxiliary combustor, a

vapor turbine, and an air compressor driven by the gas turbine, comprising:

cludes a gas turbine with an auxiliary combustor, a vapor turbine, and an air compressor driven by the gas turbine, comprising:

lower end; a dish-shaped circular member enclosing the lower end of said bell-shaped extension, said dish-shaped cirfluid heating tubes defining a chamber, said chamber including a first vertical section having a diverging cular member defining burner ports evenly located about two concentric circles;

lOWef 6nd tension, 3 Second Vertical Section, and an inlet header located adjacent and beneath said disha horizontal section connecting th upp ends of shaped circular member and connected to said fluid said first vertical section and said second vertical heating t b t th low d f aid fi t rti al section; section for supplying a vaporizable fluid to said fluid means for supplying a relatively cool vaporizable fluid heating tubes;

to said fluid heating tubes; means for supplying vaporizable fluid to said inlet mfiflns for y-p from and returning to Said means header, said supply means including a main conduit for s pplying a relatively C001 vaporizable fluid, a and a by-pass and return conduits; Portion of Said relatively C001 p ab fl a multiplicity of burners each located in one of said fore entering said fluid heating tubes; burner ports and directed upwardly and inwardly burner means located at the lower end of said divergapproximately t d a common i t on th ing lower end extension of said first vertical section tical longitudinal axis of said first vertical section; of Said Chamber pp y heating gases to Said an outer containment shell of circular cross section enh for flow thefetllfough t0 vaporize Said Ielflcasing said chamber, said outer containment shell tively cool vaporizable fluid; and chamber defining an air passageway therebcan outer containment shell encasing said chamber, said tween extending along said second vertical section outer containment shell a d ch m defining an and said horizontal section and said first vertical air passageway thsrsbstwssn extending along said section from the horizontal section to the lower end second vertical section and said horizontal section f id b lL h d t io id bollhaped xand said first vertical se i n d t Said divfilglng tension extending outward substantially to said outer end eXtenSiOIl, Said diverging end extension eXtend- 40 containment shell, said outer containment shell deing substantially out t0 said outer containment shell; ifining air exit means adjacent and above said bellmeans for PP y Compressed from d C0111- shaped extension and an air re-entrance means below pressor to said air passageway; and adjacent said bell-shaped extension and a heatmeans partially coextensive with said outer containing gas it means lo t d b l th lo d f mcnt Shell for pp y Compressed air from Said said second vertical section for discharging said heatair passageway to Said burn s; ing gas to said gas turbine through said auxiliary means Partially coextensive With Said Outer containcombustor and further defining an initial air entrance ment shell and in communication With the lOWfil' means located adjacent and above the, lower end of end of said second vertical section an c n e t said second vertical section for introducing air from to said gas turbine through said auxiliary combustor id i ompressor; for discharging gases from Said chamber to Said partition means extending radially between said second gas turbine; vertical section and said outer containment shell m n f structurally supporting said chamber and adjacent said lower end of said second vertical secouter containment shell; tion and between said air entrance means and said a superheater located within the second vertical secgas it means f id outer tai t h ll to tion of said chamber and connected for series flow eparate id i iti l t; entrance means f o aid of fluid from said fluid heating tubes and to said gas it means; vapor turbine; means for connecting said air exit means and said air a first reheater located in the horizontal section Of the r e-entrance means to convey the air flowing through chamber and adjacent said first vertical section, said said air passageway to said burners and around said first reheater being connected for series flow of fluid bell-shaped extension; from said vapor turbine; means for structurally suspending said chamber and a heat exchanger of the shell and tube type for conaid o t r ontai m nt h ll;

trolling the temperature of the reheated fluid by r an outlet header located beneath the lower end of moving excess heat from the reheat fluid and tranS- said second vertical section and connected to said farting Said llfi'rlt t0 the Portion of Said elatively fluid heating tubes at the lower end of said second cool vaporizable fluid by-passed from a d hea ing vertical section for receiving the fluid from said fluid tubes, said means for by-passing and returning being heating tubes, said fluid heating tubes being adapted connected to the tube side of said heat exchanger, for direct flow from said inlet header to said outlet the shell side of said heat exchanger being connected header; for series flow from said first reheater; a superheater located within the second vertical seea second reheater located in the horizontal section of tion of said chamber and connected to said outlet said chamber and adjacent said second vertical secheader for series flow of fluid from said fluid heattion, said second reheater being connected for series ing tubes and to said vapor turbine; flow of fluid from said heat exchanger; and a first reheater located in the horizontal section and ada temperature control valve located in series with the jacent said first vertical section, said first reheater being connected for series flow of fluid from said vapor turbine;

heat exchanger of the shell and tube type for controlling the temperature-of the heated fluid by rere section and said outer containment shell adjacent said lower end of said rectangular vertical section and between said initial air entrance means and said gas exit means to separate said initial air entrance means moving excess heat from the reheat fluid and transfrom said gas exit means;

ferring said heat to the portion of said relatively cool conduits for connecting said plurality of air exit ports, vaporizable fluid by-passed from said heating tubes, said plurality of air entrance ports of said first vertisaid means for by-passing and returning being concal portion to convey the air flowing through said air nected in series flow to the tube side of said heat passageway to said burners and around said bellexchanger, the shell side of said heat exchanger beshaped extension of said cylindrical vertical section; ing connected 01 series flOW from said first reheater; means including a plurality of vertical posts and horisecond reheater located in the horizontal section of zontal beams supported by said vertical posts and said chamber and adjacent said second vertical secrods extending vertically downward from said horition, said second reheater being connected for series zontal beam and connected to said chamber and flow of fluid from the shell side of said heat exsaid outer containment shell for supporting said changer; and chamber and outer containment shell;

a temperature control valve connected in series with the a ring-shaped outlet header located beneath said lower tube Sidfi of said heat exchanger and adapted to be end of said rectangular vertical section and conacmated y the Outlet temperature of Said Second nected to said fluid heating tubes at the lower end reheater.

of said rectangular vertical section for receiving the 6. A vapor generator for use in a power plant which includes a gas turbine with an auxiliary combustor, a vapor turbine, and an air compressor driven by the gas turbine, comprising:

fluid heating tubes defining a chamber, said chamber including a cylindrical vertical section with a bellshaped lower extension open at the lower end, a rectangular vertical section open at the lower end, and a rectangular horizontal section connecting the a upper ends of said cylindrical vertical section and said rectangular vertical section;

a dish-shaped circular member enclosing the lower end of said bell-shaped lower extension, said dish-shaped circular member defining burner ports evenly located about two con-centric circles; 3

a ring-shaped inlet header located adjacent and beneath said dish-shaped circular plate and connected to said fluid heating tubes at the lower end of said bell-shaped extension of said cylindrical vertical section for supplying vaporizable fluid to said fluid heating tubes;

means for supplying vaporizable fluid to said ringshaped inlet header, said supply means including a main conduit connected directly to said ring-shaped inlet header and further including by-pass and return conduits connected to said main conduit for diverting a portion of vaporizable fluid from said main conduit and returning the diverted portion of vaporizable fluid to said main conduit;

a multiplicity of burners each located in one of said burner ports and directed upwardly and inwardly towards a common point on the longitudinal axis of said cylindrical vertical section;

an outer containment shell of circular cross section encasing said chamber, said outer containment shell and chamber defining an air passageway therebetween extending along said rectangular vertical section, said rectangular horizontal section, and said cylindrical vertical section from the horizontal section to the bottom of said bell-shaped extension, said bell-shaped extension extending outward to approximately said outer containment shell, said outer containment shell defining a plurality of air exit ports adjacent and above said bell-shaped lower end portion and a plurality of air re-entrance ports below and adjacent said bell-shaped lower end portion and vaporizable fluid from said fluid heating tubes, said fluid heating tubes being adapted for direct flow from said ring-shaped inlet header to said ringshaped outlet header;

primary superheater bank located within the rectangular vertical section of said chamber and extending upward from the lower end of said rectangular vertical section;

primary superheater inlet header connected to the lower end of said primary superheater and located adjacent the lower end of said primary superheater bank and adjacent said ring-shaped outlet header;

means for connecting said ring-shaped outlet header to said primary superheater inlet header;

a primary superheater outlet header connected to the upper end of said primary superheater and located adjacent the upper end of said primary superheater bank;

:a finishing superheater bank located within the rectangular vertical section of said chamber and directly above the primary superheater bank;

a finishing superheater inlet header connected to the lower end of said finishing superheater and located adjacent the lower end of said finishing superheater bank;

means for connecting said primary superheater outlet header with said finishing superheater inlet header;

a finishing superheater outlet header connected :to the upper end of said finishing superheater and located adjacent the upper end of said finishing superheater bank;

means for connecting said finishing superheater bank to said vapor turbine;

a first reheater bank located in the horizontal section of said chamber and adjacent said cylindrical section;

a first reheater inlet header connected to the end of said first reheater bank adjacent said cylindrical vertical section;

means for connecting said vapor turbine to said first reheater inlet header; 7

a heat exchanger of the shell and tube type located with in the horizontal portion of said outer containment shell for controlling the temperature of the heated fluid by removing excess heat from the reheat fluid and transferring said heat to the portion of said a plurality of heating gas exit ports located below the lower end of said second vertical section for discharging gas to said gas turbine through said auxilrelatively cool vaporizable fluid by-passed from said heating tubes, said by-pass and return conduits being connected for series flow to the tube side of said iary combustor and further defining a plurality of heat exchanger, the shell side of said heat exchanger initial air entrance ports located adjacent and above being connected for series flow from said first rethe lower end of said rectangular vertical section for heater;

introducing air from said air compressor; a second reheater located in the horizontal section of partition means including a flat ring-shaped plate exsaid chamber, and adjacent said second vertical sectending radially between said rectangular vertical tion, said second reheater being connected for series 3,263,423 1 1 12 flow of vaporizable fiuid from the shell side of said be actuated by the outlet temperature of said reheat exchanger; heater. a second reheater outlet header connected to the end of said second reheater bank :adjacent said rec- References Clted by the Exammer tangular vertical section; 5 UNITED STATES PATENTS means for connecting said second reheater outlet to 2,952,975 9/1960 Braddy 6039.18

said vapor turbine; and a temperature control valve connected in series with MARK NEWMAN P'lmary Exammer' the tube side of said heat exchanger and adapted to 10 R- D. BLAKESLEE, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 263 ,423 August 2 1966 Walter P. Gorzegno et al.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 65, for "contsruction" read construction column 6 lines 10 and 11 12 56 and 57 for "enclosure", each occurrence read chamber line 58 for "containmnet" read containment Signed and sealed this 25th day of June 1968 (SEAL) Attest:

EDWARD J. BRENNER Commissioner of Patents Edward M. Fletcher, J r.

Attesting Officer 7 

1. A VAPOR GENERATOR FOR USE IN A POWER PLANT WHICH INCLUDES A GAS TURBINE WITH AN AUXILIARY COMBUSTOR, A VAPOR TURBINE, AND AN AIR COMPRESSOR DRIVEN BY THE GAS TURBINE, COMPRISING: FLUID HEATING TUBES WITH FINS THEREBETWEEN DEFINING A CHAMBER, SAID CHAMBER INCLUDING A FIRST VERTICAL SECTION, A SECOND VERTICAL SECTION, AND A HORIZONTAL SECTION CONNECTING THE UPPER ENDS OF SAID FIRST VERTICAL SECTION AND SAID SECOND VERTICAL SECTION; MEANS FOR SUPPLYING A VAPORIZABLE FLUID TO SAID FLUID HEATING TUBES AT THE LOWER END OF SAID FIRST VERTICAL SECTION; BURNER MEANS LOCATED AT THE LOWER END OF SAID FIRST VERTICAL SECTION OF SAID CHAMBER FOR SUPPLYING HEATING GASES TO SAID CHAMBER FOR FLOW THERETHROUGH; AN OUTER CONTAINMENT SHELL FOR SURROUNDING SAID ENCLOSURE; MEANS PARTIALLY COEXTENSIVE WITH SAID ENCLOSURE AND OUTER CONTAINMENT SHELL FOR SUPPLYING AIR FROM SAID COMPRESSOR TO SAID BURNER MEANS; 